Heat-treating furnace



Y Sept. 14, 1937. E. w. WEAVER ET AL HEAT TREATING FURNACE 2 Sheets-Sheet l I Filed Feb. 15, 1957 unmun n Bnventors E. W. Wea z/er J. zL/Teece attorney Sept. 14, 1937. E. w; WEAVER ET AL 2,093,376

HEAT TREATING FURNACE Filed Feb. 15, 1957 2 Sheets-Sheet 2 Bnventors f. M 14 60, zxer J. fl. Reece attorney Patented Sept. 14, 1937 UNITED STATES PATENT OFFICE HEAT-TREATING FURNACE York Application February 15, 1937, Serial No. 125,737

4 Claims.

This invention relates to heat-treating furnaces of the type embodying a quench tank into which the heated articles are discharged from the heating chamber; and the object of the invention is to provide a furnace of this type which shall embody a rotary work carrier in its heating chamber, the carrier being provided with a multiplicity of outwardly facing work receptacles together with means for releasably confining work or articles in the receptacles as the latter point downwardly, whereby to cause the articles to be carried around to a greater number of degrees, before being discharged into the quench tank, than would otherwise be possible in the absence of such means.

' In the drawings wherein the preferred form of the invention is shown,

Fig. 1 is a view partly in section and partly in elevation of the improved furnace;

Fig. 2 is a vertical section through the furnace shown in Fig. 1;

Fig. 3 is an enlarged fragmentary sectional view of one of the receptacles in position for loading, and

Fig. 4 is a small scale view illustrating a modified form of receptacle.

The heating chamber of the furnace is indicated at I0 and it is heated in any preferred way as by gas burners of which one is indicated at I I in Fig. 1. Extending across the furnace chamber for rotation on a horizontal axis is a work carrier shown as a drum I2, whose ends are reduced and extended as shafts I3 and I4 which are supported in suitable bearings I5 outside of the furnace chamber. The drum is rotated by any preferred means shown as a gear I6 on shaft I4 driven by a pinion I'I forming part of a speed reducer I8 coupled to a motor I9.

Secured to the outside face of the drum I2 in 'circumferentially spaced relation are work receptacles generally indicated at 20 and which extend lengthwise of the drum or in other words in parallelism with its axis.

As shown in Figs. 1-3, the receptacles are of radial slot type, the slot being indicated at 2|.

Receptacles of this type are particularly well adapted for receiving strip material, such as saw blades. However, the receptacles need not necessarily be of slot type since it is the shape of the work which determines, to a greater or less degree, the particular shape of the receptacles. When of slot type, each receptacle may comprise a pair of parallelly extending plates 22 arranged in spaced relation to form the walls of theslot 2|, the plates being secured to the periphery of the drum as by cap screws 23. The plates are shown as braced on their back sides by ribs 24 and also as having a multiplicity of apertures 23 which serve the double purpose of reducing the weight of the receptacles and also of permitting gases in the heating chamber to have free access to the interior of the receptacles.

The receptacles are loaded one at a time as they come opposite a door opening 26 in the front side wall of 'the furnace, said opening being normally closed by a lifting door 2'I,-the loading being done by hand in the furnace as illustrated. As viewed in Fig. 2, the rotation of the drum or carrier I2 is clockwise as indicated by the arrow inside of the drum. It will be noted that the door opening 26 is at such a level with respect to the axis of the drum that the receptacle to be loaded is in horizontal position. As a receptacle moves upwardly and then downwardly to a point about 180 from its loading point there is, of course, no tendency for the work to fall out of the re- 'ceptacle but beyond that point there is. Now the object of the present invention is to provide a relatively simple mechanism for releasably confining the articles in the receptacles after they point downwardly to the end that the work carrier may be rotated a greater number of degrees before the work is discharged therefrom thereby materially increasing the utility of the furnace as a whole.

In accordance with the present invention, there is provided, for each receptacle 20, a swinging gate 28'which is hinged as at 29 to the lower side of the receptacle as the latter is viewed in front of the door opening 26. When in this position the center of gravity of the gate is below its hinge and the face 28' of the gate is at an upwardly extending angle as indicated in Fig. 3. The gate is shown as provided with a stop finger 30 which limits its swing in a counter-clockwise direction as viewed in Fig. 3, for reasons presently explained. When the receptacle is of slot type and the work to be heat treated is strip material substantially as long as the receptacle, then the gate need not be laterally continuous but may consist of separate gate elements rigidly connected together by a cross-bar 3| as clearly shown in Fig. 1.

Since the gates are simply hinged to their respective receptacles and, therefore, hang pendant in moving upwardly toward and away from loading position, it will be readily appreciated that at some point between and removed from the loading point, gravity will cause the gates to swing clockwise into receptacle-closing position,

as will be readily understood by reference to Fig. 2. It will also be recognized that at some point less than 90 ahead of the loading point, gravity will cause the gates to swing counter-clockwise into receptacle opening position. The stop finger 30 of each gate is also a factor in determining the time whenthe. gates swing. over to close the receptacles, since, except for the stop finger, the gates would tend to assume a pendant position somewhat more toward the right as regards the lower end of the gate as viewed in Fig. 3. However, the primary purpose of the st6p..fihger?30 is to prevent the gates from swinging sufficiently far in a counterclockwise direction, when. attheQ, loading side of the furnace chamber, to..cause the lower end of that gate which is next above the receptacle which is in position for loading from interfering with the mouth of the last men'- tioned receptacle. spacing of the receptacles, the lower end or crossbar 3| of the; gate would not interfere with'the' next lower receptacle aswill be readily understood. l V

' As each receptacle 20 reaches its lowermost point of travel, its'gate is automatically released or opened, by means presently described, :to per-' mitthe contents of the receptacle to pass out of the furnace through an upright chute 32' leading into a quench tank 33. When the. work being heat-treated is strip material, such as saw blades, there may be provided below the chute a clamping device generally indicated at 35for clamping the strip to prevent it from warping while being quenched. J Thejaws of this vclampingidevice are indicated at 36-andi3'l, the jaw 31 being fixed and the jaw 36 being laterally movable with respect' thereto by any appropriate means shown as including a'thrust rod 38- which extends through the. side wall of the quench tank. The faces of the jaws are shown'as provided with a multiplicity of aligned oppositely extending'fingers between the adjacentendsof'which the strip is clamped, the purpose 'of' the fingers being to permit quenching liquid to have free access to the strip material. .Directly below the clamping'device is a laterally movable'stop 39which prevents the strip from passing'downwardly between the jaws prior to being clamped therebetween. After the strip has been clamped, the stop 39 is moved laterally by, any preferred means'shown as apull' rod 40 extendingout'through the sidewall of thequench tank with the result that after the jaw, 3'6'ismoved away from clamping position,'the blade will drop. onto an endless conveyor C and thus be' carried out of Itheta'nk. The clamping mechanism 35 forms. no part ofthe present invention but has been briefly described merely to give a better understanding of the heat-treating apparatus .as a whole.

The-mechanism for automatically opening the gate of that receptacle. which'is in a position above the chute 32,to discharge its-contents into the latter will next bedescribed. Extending intothe'furnace chamber Iii, adjacent the lower part thereof,.1i-s .a crankshaft 4| supported in suitable bearings 42' outside of the chamber. The

crank of this shaft is within the furnace chain:

ber l0. and hasa crank pin 45 which extends into the. path of travel of the crossbar lower end of the gate, the arrangement being such that by turning the shaft .41 in the properdir'ection, the gatewilllbe swung open to a sufiicient' degree to permitthework in the receptacle to pass into e the chute 32,as will now be readily understood.

Turning' movement is imparted to the shaft 4| With wider circumferential-- at the proper time by any preferred means, which, for descriptive purposes, may be considered'as an electrically actuated device 46 connected to the shaft 4|. It should perhaps be stated that rotation of the drum I2 is periodically stopped by means not shown to permit loading and unloading of the receptaclesand that the electrical device 46 is not actuated to turn the shaft to open the gate until the drum has been stopped.

. I It will be readily appreciated that instead of being laterally continuous or of. slot type the receptacles mayeach comprise a row of individual receptacles, as indicated at 2| in Fig. 4, in which event thegface of: the gatewould ordinarily be laterally continuous as indicated at 28". 3| indicatesa lateral extension of the gate for cooperative engagement with the gate-opening crank shaft'fl. The drum is indicated at I2.

From the foregoing description it will be seen that the present invention provides a heat-treating. furnacewhich is relatively simple in construction and well adapted for its intended pur-' pose. It will. also be readily appreciated that receptacles of the slot type are well adapted for holding strip material, such as saw'blades, whereas a rowof receptacles 2| asin' 4 are particularly well adapted for holdlng'relatively small pieces of. work. What is'claimed is:

l. A heat treating furnacecomprisingfln'combination, a heating chamberhaving a lateralopening for the entry of work, a work carrier rotatably mounted within said chamber .on. a'

" ed within said chamber on a horizontal axis and having radial work receptaclesat'spaced'distances onits outer periphery, closure gates for the outer end of each receptacle-swingably hung on the carrier and operable by gravity to form abarrier against: exit of work from said receptacles as the receptacles are rotated through a downward path and toremove any barrier against entrance of Work as the receptacles move upwardly, and means independent of the carrier for tripping said closure gates to permit discharge of work from said receptacles and heating cham ber through the discharge chute.

3. .A heat treating. furnace comprising, in combination, a substantially fully enclosed heating chamber having a lateral opening for the entry of work and a bottom work discharge chute, a work carrier drum. rotatably mounted within said. chamber on. a horizontal axis and'having radial slots forming work receptacles at uni.- formly spaced distances on the outer circumference of the drum, means for rotating said a direction to carry the freshly'entered work upwardly and away fromsaid entry opening,

carrier with aregularly intermittent motion in V and closure gates for the'outer end of each rejceptacle swingably hung on. the carrierand operable by gravity; to form a. barrier against exit of work fromthe receptacles when the receptacles point downwardly as they are rotated through a downward path and to remove the barrier against entrance of work as the receptacles move upwardly past the lateral opening.

4. A heat treating furnace comprising, in combination, a substantially fully enclosed heating chamber having a lateral opening for the entry of work, a quench tank underlying the heating chamber, a restricted Work discharge chute communicably connecting the interior of the heating chamber with the quench tank, a work carrier drum rotatably mounted within the chamber on a horizontal axis, radial slots positioned at spaced distances around the circumference of the drum forming work receptacles, means for rotating said carrier with a regularly intermittent motion in a direction to carry the freshly entered work upward and away from said lateral opening, closure gates for the outer end of each receptacle swingably hung on the carrier and operable by gravity after the carrier has moved the receptacles past their highest point of travel to close the mouths of the receptacles against exit of Work as the receptacles are rotated through a downward path and to open the receptacles to permit entry of work as the receptacles move upwardly after passing their lowest point of. travel.

ERNEST W. WEAVER. JOSEPH A. REECE. 

